Hi folks, another newbie question. Not sure if this is the right forum as it seems more specialized with display LEDs, but I figured this might be the best forum to post this.

So I'm looking into controling several LED lighting circuits (abour 3-5W per circuit @12VDC). I've been looking at a lot of existing products out there, and most of them require LED "drivers" to drive them. So my question is: are the so-called LED drivers just bonefied AC-DC power supplies, or is there something special about these drivers?

And if I wanted to build a circuit to control (i.e. switch on and off) these LEDs circuits via the Arduino without using relays, any suggestion as to what type of circuit I should use? Assuming my power supply has enough juice, would a simple Dralington transistor suffice?

Finally, if I wanted to get fancy and try to dim these LEDs, would PWM work for dimming LEDs?

3-5W is a lot of current: 2.4A with 5W, 12V. You'd want something MOSFET based with real low Rds so they don't burn up. And to ensure they change states fast from low Rds (full on) to the off state, you need a MOSFET driver. That combination is what makes the LED driver.

It depends on what you are driving. Driving high powered LEDs require a constant current source where as driving lots of low power LEDs together so you require a large current just requires a normal power supply.

LED drivers are designed to drive LED loads typically in a constant-current (CC) mode. Some drivers are constant-voltage (CV) and require a current regulator others areCV/CC and can be operated either mode. The outputs are short-circuit (SC) and open-circuit (OC) protected.

If you are looking at LED drivers with an AC input these will typically have power-factor (PF) correction. Since there are a lot of outdoor LED applications a number ofdrivers will have outdoor ratings for moisture as well as surge protection.

Hmm, I remembered seeing 0.3-2.5V on the data sheet but I guess this is just for the analog dimming. I guess it wouldn't really make sense to have a 0.3V PWM signal. I guess I used up a bunch of resistors for nothing XDCarry on, let us know how it goes!